Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.21/4982
Registo completo
Campo DCValorIdioma
dc.contributor.authorPatrício, Pedro-
dc.contributor.authorAlmeida, Pedro L.-
dc.contributor.authorPortela, R.-
dc.contributor.authorSobral, R. G.-
dc.contributor.authorGrilo, I. R.-
dc.contributor.authorCidade, T.-
dc.contributor.authorLeal, Catarina Marques Mendes Almeida da Rosa-
dc.date.accessioned2015-08-25T10:30:36Z-
dc.date.available2015-08-25T10:30:36Z-
dc.date.issued2014-08-
dc.identifier.citationPATRÍCIO, Pedro Manuel Alves, [et al] – Living bacteria rheology: Population growth, aggregation patterns, and collective behaviour under diferente shear flows. Physical Review E. ISSN: 1539-3755. Vol. 90, nr. 2 (2014), Art. nr. 022720por
dc.identifier.issn1539-3755-
dc.identifier.issn1550-2376-
dc.identifier.urihttp://hdl.handle.net/10400.21/4982-
dc.description.abstractThe activity of growing living bacteria was investigated using real-time and in situ rheology-in stationary and oscillatory shear. Two different strains of the human pathogen Staphylococcus aureus-strain COL and its isogenic cell wall autolysis mutant, RUSAL9-were considered in this work. For low bacteria density, strain COL forms small clusters, while the mutant, presenting deficient cell separation, forms irregular larger aggregates. In the early stages of growth, when subjected to a stationary shear, the viscosity of the cultures of both strains increases with the population of cells. As the bacteria reach the exponential phase of growth, the viscosity of the cultures of the two strains follows different and rich behaviors, with no counterpart in the optical density or in the population's colony-forming units measurements. While the viscosity of strain COL culture keeps increasing during the exponential phase and returns close to its initial value for the late phase of growth, where the population stabilizes, the viscosity of the mutant strain culture decreases steeply, still in the exponential phase, remains constant for some time, and increases again, reaching a constant plateau at a maximum value for the late phase of growth. These complex viscoelastic behaviors, which were observed to be shear-stress-dependent, are a consequence of two coupled effects: the cell density continuous increase and its changing interacting properties. The viscous and elastic moduli of strain COL culture, obtained with oscillatory shear, exhibit power-law behaviors whose exponents are dependent on the bacteria growth stage. The viscous and elastic moduli of the mutant culture have complex behaviors, emerging from the different relaxation times that are associated with the large molecules of the medium and the self-organized structures of bacteria. Nevertheless, these behaviors reflect the bacteria growth stage.por
dc.language.isoengpor
dc.publisherAmer Physical Socpor
dc.relation.ispartofseries022720-
dc.rightsclosedAccesspor
dc.subjectSoft Glassy Materialspor
dc.subjectStaphylococcus-Aureuspor
dc.subjectCellpor
dc.subjectDetachmentpor
dc.subjectResistancepor
dc.subjectInsightspor
dc.subjectBiofilmspor
dc.titleLiving bacteria rheology: Population growth, aggregation patterns, and collective behaviour under diferente shear flowspor
dc.typearticlepor
dc.peerreviewedyespor
degois.publication.issue2por
degois.publication.locationUSApor
degois.publication.titlePhysical Review Epor
degois.publication.volume90por
dc.identifier.doi10.1103/PhysRevE.90.022720-
Aparece nas colecções:ISEL - Física - Artigos

Ficheiros deste registo:
Ficheiro Descrição TamanhoFormato 
Living bacteria rheology.pdf1,59 MBAdobe PDFVer/Abrir    Acesso Restrito. Solicitar cópia ao autor!


FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpace
Formato BibTex MendeleyEndnote Degois 

Todos os registos no repositório estão protegidos por leis de copyright, com todos os direitos reservados.